Bonded terminal



April 5, 1949. v VI A 2,466,012

BONDED TERMINAL Filed Jan. 13, 1945 IN VEN TOR. SAMUEL Dl VITA 1 BY 40WM$+LL ATTORNEY factured and used by or Patented Apr. 5,, 1949 TBONDED TERMINAL sam Di Vita, Long Branch, NJ. Application January 13, 1945, Serial No. 572,717

7 Claims (01. seam-27.5)

(Granted under the act'of March amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufor the Government for governmental purposes, without "the payment to me of any royalty thereon.

This invention relates to terminals for electronic tubes and the like, and mor particularly to terminals of the type having a vitreous base with a metallic coating bonded thereto. Heretofore metal terminal caps for electronic devices such as tubes have been cemented in place with the lead-in wires soldered thereto. By reason of wide variations in temperature and -moisture conditions and also because of severe mechanical vibration, cemented terminal structures heretofore used have failed due to rupture of the cemented construction.

It is an object of this invention to provide an improved metal terminal structure for electronic tubes and the like that shall have predetermineddesired electrical characteristics without being subject to failure in operation as above referred It is another object of this invention-to provide an improved terminalfor electronic tubes and- -the like which is adapted to besecurely bonded to the tube structure.

The term terminal .as used. herein'shall mean an outwardly projecting element formed on the surface of a dielectric envelope whereby connection may be made between an element positioned within said envelope and an element positioned external to said envelope, and shall be understood to include, as one element thereof, either an outwardly projecting nipple formed integral with said envelope or a convex mass of metallic coating formed in situ in suflicient quantity to form an outwardly projecting nipple bonded to said envelope. It is further intended that the word terminal shall mean a device complementary in shape and size to a clip, cap or the like, whereby the said terminal may be electrically connected to, and mechanically engaged by, the said clip or the like.

In accordance with the invention, a terminal of the desired type is provided by the use of a metallic coating bonded to an external surface area of the tube, in such a manner as to make electrical contact with a portion of the lead-in wire which has been arranged to extend externally of the envelope of the tube through said area, and in such quantity as to form a terminal.

As distinguished from known methods involving cementing terminal elements to ceramic or vitreous envelopes, the term metallic coating, or bonding, as used herein shall mean an i Z bonding of a metal to a vitreous material, which bonding may be achieved by hot spraying or any other suitable method. Obviously, the metallic coating and the vitreous material to which itis bonded must have coefiicients of expansion which are substantially identical.

For a better understanding of this invention, reference is made to the following description read in connection with the accompanying drawing.

In the drawing, Fig. 1 is a View, in elevation and partially in cross section, of an electronic device embodying the invention, and Fig. 2 is an elevational view, partly in section, of a modificationof the device shown in Fig. l.

Referring to. Fig. 1, a vitreous envelope l for the device is formed with an upper surface area as an outwardly projectin nipple 2. A lead-in or lead wire 3 constitutes a path of conductive material between an element 4 within the envelope land the exterior of the envelope. -Itis intended that the lead wire 3 shall extend but a slight distance externally of the tube. In the ;;.present1example, the wire 3 passes center of the nipple 2 andissealed therein by by any other suitable means.

adhesive aterminal.

through the fusing of the vitreous material about the wire, or

The metallic coat 5 is bonded to the vitreous material as hereinbefore described and completely covers the external surface of the nipple 2 and the portion of the wire 3 projecting externally of the said nipple 2.

It will be seen that, in accordance with the invention, an improved terminal is provided for an electronic tube or the like which is bonded to a preformed area of the envelope about a projecting lead wire terminal to form a unitary terminal for the device. In manufacture, the lead wire 3 may thus be positioned by fusion of the vitreous material about the wire, with a short length of said wire extending externally of the tube. The metallic coating may then be bonded to the preformed surface of the tube immediately surrounding the wire in such a manner as to completely embed said wire and provide electrical connection therewith.

In my preferred embodiment, I have shown the metallic coating as being bonded over a nipple on the surface of the tube. While the use of a nipple is more convenient in forming a terminal, it is within the scope of my invention to seal my lead wire at any predetermined area on the surface of the tube, and then bond a metallic coating thereover in sufficient quantity to form This modification of my invention is 3 illustrated in Fig. 2, wherein a lead wire 1 extends a short distance externally of a tube 6, and

a metallic coating 8 is bonded to the adjacent jecting vitreous nipple formed onithe said en-' velope, a lead wire sealed to andextendihg through said nipple, a metallic coating dielectrically sealed to said nipple and covering that portion of the wire external of said nipple and envelope.

2. A terminal structure for an electronic device, comprising an envelope of vitreous material having a lead wire sealed-to and extending through said envelope at a predeterminedpoint,

-.a relatively short portion of said lead wire extending externally .of said envelope, and a metallic coating embedding the said extending portion of saidlead Wire, said coating being dielectrically sealed to the externalareaof the envelope immediately adjacent tosaid lead wire, the "mass-of said metallic coating being suflicient to forma nipple engageable by a clip.

I :3. The method (if-providing a terminal for-the vitreous envelope of zanelectronic device, which comprises sealing alead wire-in the envelope with a relatively short" portion of said lead wire extending externally of said envelope; providing a metallic coating for embedding the said portion hi the leadwire-and for forming a dielectric seal with the immediately adjacent external surface of the envelope, the said metallic coating-being of suilicient mass to form a ni'pple engageab'le by-a clip.

4. The method'oi providing a terminal for the "vitreous envelope of an electronic device, which comprises sealing a lead wire in the envelope with a relatively'short portion of said lead wire'extending externally of said envelope, providing a metallic coating for embedding the said portion of the lead wire and for forming a direct metal to glass seal with the immediately adjacent external surface of the envelope, said envelope, lead wire and metallic coating having substantially identical coeflicients of expansion.

5. A terminal to electrically and mechanically connect an element within an electronic device to an external circuit, the device being characterized by a dielectric envelope, said terminal comprising -.a lead wire sealed to and extending through said envelope and a convex metallic coating disposed about said wire and adhesively bonded to said envelope in .a glass to metal seal, the mass of said coating being formed in place sufficient to form a'nipple' engaeeablelby a clip.

6. The method of providing a terminal for a dielectric envelope having an outwardly projecting vitreous nipple formed on the said envelope, which comprises sealing a lead wire in the nipple,

providing a metallic coating for embedding the 7. said externally extending portion of said wire and for securing bonding in a dielectric seal with the immediately adjacent external suriace of l the envelope.

7. A terminal structure for dielectric envelopes having a lead wire sealed through said envelope -with -arelatively short portion of said lead wire extending externally of said envelope, said 'terminal structure comprising a metallic coating bonded in-a dielectric seal to the surface oisaid envelope immediately adjacent said externally =-extending---wire, said coating being in electrical contactwith said externally extending lead-wire.

SAM DI VITA.

' REFERENCES CITED The following references are'of record in the flle'of this patent:

1 UNITED STATES PATENTS Number -Name Date D. 135,307 Eitel et al. Mar. 23, 1943 "71,990,728 Eitfil eta1 Feb. v12, 1935 -.2,=12 9,0 5 Loewe Sept. 6, 1938 2,200,911 Bowie '-May 14, 1940 2,202,500 Lopp May 28, 1940 -'2,329,0'l9 "Wagener Sept. 9, 1943 

